As much as I bemoan the lack of space in our tiny apartment, I don't know that I'd go as far as this couple and live in a completely different apartment than Mr. T. I kinda get where they're coming from--I have a friend who lives in a little bungalow right next to her fiancee's bungalow, and that works great for them. And I'm a girl who likes her space. (Especially her closet space.)
I begged Mr. T to move in with me, and after he did (five years into our relationship), I realized that I was the one having a hard time adjusting to living together. It turns out those two nights a week he spent at his place had actually made a big difference to me after all (I was relating this story to a friend recently and Mr. T was in the room. He exclaimed, "You never told me that!" Whoops. Sorry, honey.).
Anyway, I adjusted, and we try hard to respect each other's space, although in a tiny apartment that's tricky. I look forward to the day when Mr. T's dresser is not directly behind the bathroom door. I also look forward to someday having TWO sinks in the bathroom. Or even separate bathrooms. One of our friends swears by that.
Regardless of all these little things, I don't think I could give up sleeping in the same bed every night. I would really miss that. I particularly love weekend mornings when we can wake up slowly and then we realize that the cats are in bed with us, too--just one cozy comfy little family.
So, yes, I'd like more space, but separate apartments? Not for me!